七氟醚和异氟醚对罗库溴铵阻滞大鼠骨骼肌成人型乙酰胆碱受体的影响

Effects of sevoflurane and isoflurane on blockade of adult type nicotinic acetylcholine receptors of skeletal muscle of rats by rocuronium

目的评价七氟醚和异氟醚对罗库溴铵阻滞大鼠骨骼肌成人型乙酰胆碱受体（ε-nAChR）的影响。方法通过脂质体转染法构建表达ε-nAChR的HEK293细胞，采用全细胞膜片钳技术分别测定不同浓度七氟醚、异氟醚和罗库溴铵孵育后乙酰胆碱激动ε—nAChR的内向电流，拟合七氟醚、异氟醚和罗库溴铵浓度与ε-nAChR内向电流抑制率的浓度。效应曲线，计算3种药物抑制ε-nAChR内向电流的5％的浓度（IC5）、25％的浓度（IC50）和50％的浓度（IC50）。分别用IC5、IC5和IC50七氟醚和异氟醚孵育重组HEK293细胞，然后加入IC25，罗库溴铵共同孵育；用IC25七氟醚和异氟醚孵育重组HEK293细胞，然后用IC5、IC50、IC50罗库溴铵共同孵育；分别计算ε-nAChR内向电流抑制率。结果IC5、IC25和IC50七氟醚或异氟醚与IC5和IC25罗库溴铵抑制ε-nAChR内向电流的效应呈协同作用，而与IC50罗库溴铵抑制ε-nAChR内向电流的效应呈相加作用；IC5七氟醚与IC25罗库溴铵抑制ε-nAChR内向电流的效应弱于异氟醚，而IC50七氟醚与IC25罗库溴铵抑制ε-nAChR内向电流的效应强于异氟醚，IC25七氟醚与IC5罗库溴铵抑制ε-nAChR内向电流的效应弱于异氟醚。结论七氟醚或异氟醚与低浓度罗库溴铵阻滞大鼠骨骼肌ε-nAChR的效应呈协同作用，而与高浓度罗库溴铵的效应呈相加作用；低浓度七氟醚强化罗库溴铵阻滞ε-nAChR的效应弱于异氟醚，而高浓度七氟醚的效应强于异氟醚。

Objective To investigate the effects of sevoflurane and isoflurane on blockade of adult nicotinic acetyleboiine receptor （s-nAChR） of skeletal muscle of rats by roeuronium. Methods HEK293 cell line was provided by Molecular Biology Laboratory, Chonqing Medical University and cuhured in DMEM liquid culture medium containing 10 % bovine calf serum at 37 ℃ in incubator filled with 5 % CO2 . ε-nAChR was expressed heterologously in HEK293 cell using liposome transfection technology. The whole cell patch clamp technology was used to establish the concentration-effect curves for inhibition of acetylcboline （ACh）-induced current. The 5 % inhibitory concentration values （ IC5 ）, 25 % inhibitory concentration values （ IC25 ） and 50% inhibitory concentration values （IC50） for sevoflurane, isoflurane and rocuronium were calculated. Firstly the inhibitory effect of rocuronium at a concentration of IC25 was studied in the presence of sevoflurane and isoflurane at concentrations of IC5, IC25 and IC50. Subsequently the inhibitory effect of rocuronium at concentrations of IC5, IC25 and ICs0 was studied in the presence of sevoflurane and isoflurane at a concentration of IC25 ~ Inhibition of ACh-induced current amplitude was recorded. Results At the concentrations of IC5, IC25 and ICs0 sevoflurane or isoflurane had synergistical inhibitory effect on the current amplitude of ε-nAChR with rocuronium at the concentrations of IC5 and IC25, while had addition inhibitory effect on the current amplitude of ε-nAChR with rocuronium at the concentration of ICs0. The inhibi-tory effect of sevoflurane at the concentration of IC5 on the current amplitude of ε-nAChR with rocuronimn at the concentration of IC25 was weaker than that of isoflurane, while the inhibitory effect of sevoflurane at the concentration of IC50 on the current amplitude of ε-nAChR with rocuronium at the concentration of IC25 was stronger than that of isofiurane. The inhibitory effect of sevoflurane at the concentration of IC25 on the current amplitude of s-nAChR with rocuronium at the concentration of IC5 was weaker than that of isoflurane. Conclusion Either sevoflurane or isoflurane has synergistical blocking effect on ε-nAChR with low concentration of rocuronium, while has addition blocking effect with high concentration of rocuronium. Potentiation of blocking effect of rocuronium on ε-nAChR by low concentration of sevoflurane is weaker than that by isoflurane, while the potentiation by sevoflurane at high concentration is stronger than that by isoflurane.